The only way to do that would be to include particular typefaces as part of the CSS specification, rather than just the generic font-family keywords like “sans-serif” and “monospaced”. But who should pick them, which ones would they pick, and how would they be licensed?
It’s kind of the same problem as saying that the browser should include common images. Which images? Why? How many?
> It’s kind of the same problem as saying that the browser should include common images. Which images? Why? How many?
Images follow a different usage distribution than fonts. I'd say that the top 100 fonts are enough to render most web content, for images I'd say this is obviously different, the top 100 images might appear often but not as often as the top 100 fonts.
Google is already distributing the equivalent for text, in the form of the brotli corpus which ships in every Chrome installation.
> why don't browsers just include the most popular fonts, so the underlying OS doesn't matter?
Well, pontificating here:
1. Because many applications don't ship with additional fonts, and it's an additional layer of complexity. Some do—Microsoft Word comes to mind, IIRC.
2. Because you're still left with the same problem: unless all browsers can agree on an additional set of standard fonts, you as a web developer will only want to use those installed by Chrome and Edge and Safari and Firefox.
3. Because licensing for desktop application may (?) be more of a pain than licensing for web usage. Which may not matter for Google Fonts, since they may be the license holder for all anyway. I don't know.
Instead we're restricted to only a few fonts that actually have decent cross platform support.